By using cup plant (Silphium perfoliatum L.), which is native to North America, as bio­gas substrate, there is an economically interesting alternative or supplement to the predominantly used substrate maize. Due to its ecological advantages, it also contributes to the increase of biodiversity in the agricultural landscape. In order to establish an efficient crop stand with a long useful life of more than 10 years, a precise distribution of the seeds is necessary. The seeds are characterized by a strong heterogeneity in size and shape within a seed batch which negatively affects the quality of singling. The aim of the experiments was to quantify the size and geometry of seeds from different batches. In this context, seeds were measured and divided into fractions by using a self generated scheme and procedural analyses. In addition to optimize the singling by increasing the homogeneity, the study supports also the potential for improving the quality of commercially available seeds